Electrolytic marking apparatus



April 21, 1964 .1. F. MCMAHON, JR

ELECTROLYTIC MARKING APPARATUS 3 Sheets-Sheet 1 I INVENTOR.

\B'YJAMES F. MC MAHON,JR.

\llllll Filed Feb. 5. 1962 ATTORNEYS J. F. M MAHON, JR

ELECTROLYTIC MARKING APPARATUS April 21, 1964 3 Sheets-Sheet 2 Filed Feb. 5, 1962 FIG?) JAMES 5: MO MAHON,JR.

ATTORNEYS April 21, 1 J. F. MCMAHON, JR

ELECTROLYTIC MARKING APPARATUS 3 Sheets-Sheet 3 Filed Feb. 5, 1962 INVENTOR.

AMES E M6 MAHON,JR.

ATTORNEYS United States Patent 3,136,141 ELECTROLYTEC APPARATUS James F. McMahon, .112, Cleveland, Ohio, assignor to The Electromark Corporation, a corporation of Glade Filed Feb. 5, 1962, Ser. No. 1714389 15 Saints. (Cl. 204-224) My invention relates to apparatus for the electrolytic marking of metal articles.

An object of my invention is the provision for manipulating an electrolytic marking device to sequentially mark a plurality of metal articles with the device.

Another object is the provision of automatic means for sequentially moving an electrolytic marking device to and from a location where articles are to be sequentially marked by the device.

Another object is the provision of apparatus for automatically moving an electrolytic marking device to and from a location where successive articles are positioned for marking by the device.

Another object is the provision of apparatus having an electrolytic marking device moved to and from an article marking position in a sequence and in timing cycle wherein the periods of time for the movements of the device and intervals therebetween may be predeterminately set.

Another object is provision of means for readily adjusting automatic electrolytic marking apparatus to the location of or elevation where a series of articles are to be consecutively marked.

Another object is the provision of electrolytic marking apparatus adjustable to the kind and nature of the marking to be performed.

Another object is the provision of improved apparatus for automatically operating movement of an electrolytic marking device through a sequence for the efficient and rapid electrolytic marking of a plurality of metal articles in sequence.

A still further object is the provision for producing superior results by a novel and highly useful apparatus.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a front view of my improved apparatus mounted in a cabinet;

FIGURE 2 is a plan view of my apparatus mounted in a cabinet with a portion of the cabinet removed and showing parts of the apparatus partially in section;

FIGURE 3 is a view looking at the right-hand end of the apparatus shown in FIGURE 1 and with the wall of the cabinet removed to illustrate the working parts of the apparatus;

FIGURE 4 is an enlarged View showing detail of the mechanism for adjusting the height of the plug upon which parallel arms of the apparatus swing; and

FIGURE 5 is a view of the circuit, including components in diagrammatical form, of the electrical system embodied in my apparatus.

My apparatus has the major portion of its parts contained in a housing denoted generally by the reference character 12. This housing 12 with the apparatus mounted therein is carried on a supporting base 11 to which it is firmly secured by bolts 13 so that the elevation of the apparatus relative to the supporting base 11 remains constant. Mounted to the base 11 is a holder 14 for supporting a work piece 15 at a proper elevation for electrolytic marking of the top surface of the work piece 15. The position of the holder 14 is adjustably determined relative to the base 11 and then fixed at a predetermined position by screws or clamps, not shown. The holder 14 has shoulders or abutments so that successive ice work pieces of a plurality of work pieces may be readily and quickly positioned at a fixed location on the holder 14. The work pieces 15 may be any objects of appropriate metal subject to electrolytic action for the marking of designs or indicia thereon; for example the articles 15 may be steel tools, knives, or other articles upon which marks are to be made by an electrolytic etching action. As seen in FIGURES 1 and 3, the holder 14 is carried on the base 11 at a position somewhat forwardly of the cabinet 12 so as to locate the work piece under an electrolytic marking device.

A suitable electrolytic marking device is carried by my apparatus in a manner so as to sequentially move the electrolytic marking device downwardly into contact with the top surface of a work piece 15. Upon the raising of the electrolytic marking device by my apparatus, successive unmarked work pieces may be placed on the holder 14, either by manual substitution or by a conveyor system, in such manner that successive pieces are moved under the electrolytic marking device in each interval during which the electrolytic marking device is raised upwardly away from the holder 14.

There is shown an electrolytic marking device by way of example which comprises an electrolytic stencil 16 secured to a carbon electrode button or end-piece 17 which is physically and electrically connected to a metal electrode stem 18. The electrode stem 18 extends axially forwardly through a reservoir 1?, which reservoir 19 contains a supply of electrolytic solution. The solution in the reservoir leaks or drips downwardly through small openings in the electrode button 17 to maintain in a moistened condition the absorbent padding contained in the stencil 16. The stencil 16 is cut or imprinted with the design or indicia to be electrically etched on the work pieces 15.

The stem 13 has its upper end clamped by a clamping screw assembly 28 to a link member 27 in such manner that the axis of the electrolytic marking device is held in a vertical direction and such that the stencil 16 has its lower face maintained parallel to the upper surface of the work piece 15. The upper protruding end of the stem 13 is electrically connected to a Wire 21 of the electrical system incorporated in the apparatus by means of a con nection 2%. Thus the electrolytic marking device is connected to one pole or side of an electrical circuit used for energization of the electrolytic action. The metal work holder is is electrically connected with a wire 22 of the electrical c rcuit used for energizing electrolytic action, the wire 22 being physically and electrically connected to the work holder 14 by a connection or metal clamp 23. As the wires 21 and 22 are connected to the electrical circuit used for energizing the electrolytic action, it is seen that the electrolytic solution saturating the stencil 16 is electrically connected to one side of the circuit and the metal work piece on the metal holder 14 is electrically connected to the other side of the electrical circuit providing the electrolytic action.

Mounted to and supported by the bottom of the cabinet is an upright support column member 31 which has its base supported on a bracket foot 33. By means of the bracket 33, the column member 31 is firmly supported in a vertical position and normal to the base 11 upon which the housing 12 is supported. The bracket 33, in turn, is supported on a horizontally disposed support plate 13% secured to the cabinet along the bottom wall thereof so that the plate 39 provides strength and rigidity for the support of the column member 31 and the parts carried thereby. At the forward end of the supporting plate 30 at a location spaced from the column member 31 is an upright slotted guide member 29. As seen in FIGURES 2 ad 3, the guide member 29 extends in a vertical position and parallel to column member 31. The guide member 29 has a longitudinal slot extending substantially through the upper portion of its length so as to provide a vertically disposed guideway.

Carried by the column member 31 is a block member 37 which is adapted to be moved upwardly and downwardly relative to the column member 31. The block member 37 may be adjustably moved upwardly and downwardly in a gradual and precise manner by a long actuating threaded bolt 40 which is rotatively supported by a bracket head 32 secured to the top of the column member 31. The bolt 40 may rotate relative to the bracket head 32 but it may not move in a vertical direction relative to the bracket 32. The lower portion of the bolt 40 is threaded to provide the threaded portion 40a, which threaded portion is threadably interengaged with the block member 37. The upper end of the bolt 49 has a knurled knob 46]; non-rotatively secured thereto so that rotation of the knob 40b rotates the bolt 49 and with it the threaded portion 40a. This rotation of the bolt 40 raises and lowers the block member 37 in correspondence with the direction ofrotation of the bolt 49.

The column member 31 is provided with two vertically disposed and spaced elongated slots 34 and 35. Secured to the block member 37 and extending through the upper slot 34 is a locking bolt 41 non-rotatively secured, such as by welding, to the block member 37. This locking bolt 41 has a washer 42 mounted thereon in the position next adjacent to the side of the column member 31. A cylindrical sleeve 43 is mounted on the bolt 41 next adjacent to the Washer 42. The outer end of the bolt 41 is threaded and a knob 44 having internal threads is threadably mounted on the outer end of the bolt 41. By turning the knob 44 in one direction, it forces the sleeve 43 and washer 42 toward and against the column member 31 so as to cause frictional engagement of the washer 42 with the side of the column member 31. This tends to lock or clamp the block member 37 to the column member 31. By loosening the knob 44, this locking action is reversed so that the block member 37 is free from being locked to the column member 31 by the engagement of the washer 42 against the side of the column member 31.

A similar-assembly of nut bolt 41, washer 42, sleeve 43, and knob 44 is disposed at a lower elevation so as to extend through the lower slot 35 in the column member 31. By loosening both of the upper and lower knobs 44, the block member 31 may be moved upwardly and downwardly by rotation of the long bolt 40. After the block member has been positioned at the desired elevation, then the upper and lower knobs 44 are turned so as to press the two washers 42 against the side of the column member 31 and thus to lock at two vertically spaced positions the block member 37 securely at the desired elevated position relative to the column member 31.

There are provided two parallel arm members 25 and 26, arranged with the upper arm 25 spaced from the lower arm 26 but disposed parallel to each other in the same vertical plane. The inner end of arm 25 is pivotally carried by a pivot mounting 38 to the block member 37. Similarly, the inner end of the arm 26 is pivotally carried by the pivot mounting 39 to the block member 37. Thus the parallel arms 25 and 26 may swing upwardly and downwardly on their respective pivots supported by the block member 37 which, in turn, is supported at an adjusted elevation by the column member 31. The arms 25 and 26 are guided in their swinging action within the vertical plane by the slot or guideway in the guide member 29. The arms extend through an elongated opening or slot in the front of the cabinet 12.

Pivotally mounted to the outer or free ends of the arms 25 and 26 by means of pivot mountings 68 and 69 is the link member 27. Pivot mounting 68 pivotally secures the forward free end of arm 26 to the lower link member 27. Pivot mounting 69 pivotally secures the forward free end of arm 25 to the upper end of the link member 27. Thus pivotal movement of the link member 27 relative to the arms 25 and 26 is permitted. The spacing of the pivot mountings 68 and 69 is the same as the spacing of the pivot mountings 39 and 38 at the ends of the arms carried by the block member 37. Thus as the arms 25 and 26 may be swung upwardly and downwardly upon their respective pivots 39 and 38, they are maintained in a constant parallel relationship. Also the vertical dimension of the link member 27 is maintained on a constant vertical axis which is parallel to the axis of the block member 37.

The link member 27 is preferably made of an insulating material such as Bakelite or other appropriate electrical insulating material. If not all of the link member 27 is of insulating material, at least the forward portion thereof which engages the electrode stem 18 is of insulating material so that the stem 18 is electrically insulated from the metal arms 25 and 26 and metal parts of the apparatus connected thereto. The material of which the link member 27 is comprised is such that the clamped screw assembly 28 may readily compress the split forward end of the link member 27 to tightly engage and hold the electrode stem 18.

Carried by the block member 37 adjacent the lower portion thereof and extending at right angles thereto is a bracket plate 36 which moves upwardly an downwardly in the cabinet with the block member 37 as its position is adjustably determined. Thus the elevation of the plate bracket 36 is constant relative to the positions of the pivot mount ngs 38 and 39 also carried by the block member 37 Mounted upon the plate bracket 36 is an electric motor 46 of appropriate design and capacity, which motor 46 is raised and lowered with the plate bracket 36. This motor 46 has a motor shaft 47 extending horizontally and normal to the plane of the plate bracket 36. Non-rotatively secured to the outer end of the shaft 47 is an eccentric driving device 48. This eccentric driving device 48 is a round disk secured to the shaft 47 so as to rotate therewith. A crank arm 56 has its lower end connected by a pin connection 51 to the device 48 adjacent one of the sides thereof at a distance from the axis of the shaft 47. This provides that the crank mm or rod 50 is reciprocated by rotation of the device 48. This in effect makes the head 48 an eccentric driving device which translates the rotary motion of the motor shaft to a reciprocating motion of the crank arm or rod 50. The pin connection 51 is connected to the round head 48 forwardly thereof so as not to interfere with the rotary motion of the head or device 48.

Secured to the outer circumferential surface of the round head or device 48 is a camming projection 49 which may be readily provided by the head of a threaded bolt extending radially of and secured to the round head or rotatable driving device 48. This camming projection 49 revolves with the head or device 48 and extends outwardly from the circumferential surface thereof.

Also mounted upon the plate bracket 36 and movable therewith are microswitches 61 and 62 disposed on opposite sides of the axis of shaft 47 and of the head 48 mounted thereon. The microswitch 61 has a springbiased contact finger 61a urged toward the axis of the shaft 47. Similarly, the microswitch 62 has a springbiased finger 62a urged toward the axis of the shaft 47. These fingers 61a and 62a are automatically operated by the camming engagement of the camming projection 49 moving against the finger as the camming projection revolves around the axis of the shaft 47. Thus first the switch 61 is actuated to a closed position and next the switch 62 is actuated to a closed position, the closing of the switches 61 and 62 being alternate so that when one is closed the other is open and vice versa. The switches 61 and 62 are connected in the electrical circuit of the system as shown in FIGURE 5.

The upper end of the crank arm or rod 50 extends into an axially aligned sleeve or cylindrical sleeve 52 and axially through a coil spring 53 concentrically mounted around the rod 50 within the sleeve 52. The

uppermost end of the rod 50 is engaged at the top of the coil spring 53 so that downward movement of the rod 50 urges the spring 53 to compress against its resilient bias unless the sleeve or cylinder 52 correspondingly moves downwardly with the rod 50. The lower end of the spring 53 is anchored or biased to a shoulder or restricted lower end 52a of the sleeve 52 so that the spring 53 is biased to urge the sleeve 52 downwardly relative to the rod 50. The upper end of the sleeve 52 has a connected portion 521) which is pivotally connected to the arm by loosely fitting through a transverse opening in the arm 25. The end of the portion 52b extended through the arm 25 is secured thereto by a cotter pin 54.

By the arrangement shown, rotation of the shaft 47 by the motor 46 causes the crank arm 5!) to reciprocate. The bias of the spring 53 tends to cause the sleeve member 52 to reciprocate with the rod 50 so that in effect the rod 50 and sleeve 52 move together as one connecting member between the eccentric driving device 48 and the arm 25. Normally the spring 53 is fully expanded and merely holds the rod 59 and sleeve 52 in extended position relative to each other as shown, for example, in FIGURE 3. Thus reciprocation of the connecting member made up of rod 55 and sleeve 52 swings the arms 25 and 26 upwardly. As arm 26 is pivotally connected at its opposite ends with block member 37 and link member 27, the arm 26 similarly swings up and down in unison with the arm 25'. Swinging up and down of one arm correspondingly swings up and down the other arm.

Upon the arms meeting resistance to their downward movement, such as for example by the stencil 16 meeting resistance to its downward movement against the work piece 15, which resistance is beyond a predetermined degree, the spring 53 is compressed so as to accommodate itself to the resistance encountered. If it were not for the yieldability afforded by the spring 53, then some of the parts could break or the motor could stall by reason of the resistance encountered to the downward movement of the arms 25 and 26. The resistance required to cause the spring 53 to yield may be adjustably determined by the setting of the bias of the spring 53.

Included in the electrical circuit and system is a timing mechanism 55' which may be set from the front of the cabinet to provide desired periods of time for the sequence of operation. A voltage regulator 56 which may be set from the front of the cabinet provides for the setting of the desired voltage for the electrolytic action afforded by the circuit to the electrolytic marking device through the wires 21 and 22.

For some electrolytic etching action, a DC. supply of current is desired and for other electrolytic etching action, an A.C. supply of current is desired. To provide for ready switching from one type of current to the other, a switch 57 operable from the front of the cabinet is provided. As the apparatus may be operated either manually, that is, by manual switching for each swinging action of the arms 25 and 26, or automatically, that is, by the electrical system with the timer sequentially moving the arms through a cycle of actions in accordance with predetermined timing, a switch 58 is provided which is operable from the front of the cabinet for putting the system into manual operation or automatic operation. Signal lights 59 and 6t), observable from the front of the cabinet, indicate the how of current through the parts of the circuit where interconnected, as shown in FIGURE 5. A plug or connecting member 63 connected to the electrical circuit is adapted to be connected to a source of current, as for example, a source of alternating current. A foot switch 64 is provided for operation of the circuit to control the up and down movements of the arms 25 and 26 through actuation of the switch 64 by the operator when the system is on the manual control arrangement. A suitable transformer 65 is connected in the circuit as shown in FIGURE 5 to provide the desired voltage for the electrolytic marking action, as such voltage 6 is preset by the voltage regulator 56. A circuit breaker 66 is transposed in the circuit as illustrated in FIGURE 5. A rectifier 67 is connected in the circuit as illustrated to provide direct current for the wires 21 and 22 when desired and by appropriate switching of the switch mechanism 57.

In the usual operation of the apparatus, the switch 58 is first turned for manual operation, then by operation of the foot switch mechanism 64, the motor 46 can be actuated as desired to raise or lower the arms 25 and 26. It requires a separate actuation of the foot switch mechanism 64 to obtain each upward and each downward movement of the arms 25 and 26. While being thus manually operated, the position of the holder 14 and the work piece 15 may be adjusted and at the same time the knob 4% may be actuated to elevate the block member 37 to the required elevational position. This will enable the stencil 16 of the electrolytic marking device to be brought down in firm contact with the top surface of the article 15 to be marked but without undue compression of the spring 53. This thus permits a fine adjustment of the lowermost position to which the stencil 16 is moved so that just the right contact and pressure of the stencil 16 against the article 15 is obtained. After the required adjustment is thus obtained, the two knobs 44 are tightened so that the block member 37 is at a fixed elevational position. In this position, the spring 53 will be compressed, but very slightly, when the stencil 16 engages the top surface of the work piece 15. Depending on the type of electrolytic action to be obtained, for example, as to whether a dark or a. light colored outline of the marking to be etched is desired, a switch 57 is operated to either its A.C. or DC. position. Depending upon the nature of the material of the work piece 15 and the nature of the design or indicia to be marked thereon, the timing device 55 is set. This will determine the time interval during which the stencil 16 will remain in contact with the top surface of the work piece 15 before the arms 25 and 26 raise the stencil 16 upwardly.

The limit switches 61 and 62 so control the energization of the circuit providing the electrolytic action, that the current is supplied through wires 21 and 22 for the electrolytic action when the stencil 16 is in downward position in contact with the top surface of the work piece 15 and is disconnected when the arms 25 and 26 raise the electrolytic marking device. 4

It is thus seen that with the components and electrical system here shown and described, and which are illustrated diagrammatically in the showing in FIGURE 5, an efiicient and economical manner of obtaining electrolytic marking is provided. The invention provides for rapid and sequential electrolytic marking of a plurality of articles or work pieces to be marked as they are moved, either manually or by a conveyor, in sequence under the stencil 16 of the electrolytic marking device.

The present disclosure includes that contained in the appended claims, as well as that of the foregoing description.

Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.

What is claimed is:

1. Electrolytic marking apparatus comprising the combination of a base, work-piece engaging means supported in juxtaposition to said base to hold a work-piece at a reference location relative to said base, a column member carried by said base in upright position, a block mem ber adjustably movable along said column member to selected elevated positions, adjusting means for adjustably moving said block member along said column member and securing the block member at a selected elevated position, a pair of parallel arms having their inner ends pivotally connected to said block member at spaced locations, a link member pivotally connected to the free ends of said arms at spaced locations, an electrolytic marking device having an electrode disposed axially thereof and carried by said link member in upright position, said electrolytic marking device having a laterally disposed face portion adapted to opposingly abut a work-piece held by said engaging means during electrolytic marking of said work-piece, an electric motor carried by said base, an eccentric driving device rotatable by said motor, connecting means interconnecting said eccentric driving device and a said parallel arm to swing said parallel arms up and down by the rotation of said eccentric driving device, said connection means including resilient means to resiliently yield upon the said arms being swung downwardly beyond a limit determined by the position of a said work-piece opposingly abutted by said face portion of the electrolytic marking device, and automatic timing means controlling the actuation of said eccentric driving device to predeterminately fix the time periods of the up and down motions of the said arms and rests at the limits of movement of said arms.

2. Apparatus for moving an electrolytic marking device in a sequence of movements toward and away from an article of a series of articles consecutively positioned for marking by said marking device, comprising in combination, a pair of parallel arms, an arms-supporting block, an elongated member at a reference location carrying said arms-supporting block at variable positions therealong, adjusting means for adjustably fixing the position of said arms-supporting block along said elongated member, first pivot means pivotally mounting individually the inner ends of said parallel arms to said arms-supporting block, a link member disposed parallel to said arms-supporting block, second pivot means pivotally mounting the free ends of said parallel arms to said link member to maintain the link member in said parallel relationship in all positions of said arms swingable on said first and second pivot means, said link member being adapted to carry said electrolytic marking device in a swinging movement and in a path parallel to said link member and to said arms-supporting block, a bracket member carried by said armssupporting block to be moved therewith relative to said elongated member, an electric motor carried by said bracket member, a driving member driven by said motor, a reciprocal member connected to said driving member and one of said arms to swing said arms alternately toward and away from said bracket member and thereby to move a marking device carried by said link member alternately toward and away from an article to be marked and held at a fixed location relative to said reference location, yieldable means-associated with said reciprocal member to progressively yield upon said arms meeting resistance to movement toward said bracket member, and timing means for automatically controlling the operation of the motor to obtain a timed cycle in the movements of said arms.

3. Apparatus for automatically and sequentially positioning an electrolytic marking device at a location for electrolytically marking articles placed at said location, comprising in combination, parallel-arm means for carrying a said marking device to and away from an article at said location in a path normal to the plane of the surface of the article to be marked, support means pivotally carrying said parallel-arm means to permit the parallel-arm means to swing on said support means, adjustable means for adjustably determining the position of said support means relative to said plane, operating means carried by said support means and movable therewith relative to said plane by said adjustable means, said operating means including an electric motor and a rotatable eccentric driv ing connection powered by said motor, electric circuit means adapted to electrically connect said motor with a source of electrical current, reciprocal means connected to said driving connection to be reciprocated thereby and connected to said parallel-arm means to swing the same on said support means, and electric control means connected to said electric circuit to operate said motor and to govern the swinging of said parallel-arm means and the movement of said marking device carried thereby to and from an article at said location.

4. Apparatus as claimed in claim 3 and in which said reciprocal means includes resiliently yieldable means adapted to resiliently yield upon said parallel-arm means meeting resistance beyond a predetermined degree in swinging in a direction to carry the marking device to a said article.

5. Apparatus as claimed in claim 3 and in which said electric control means include selective switch means for permitting manual switching of said electric circuit to operate said motor as desired and automatic timing means for automatically controlling the switching of said electric circuit to operate said motor in a predetermined timed cycle.

6. The combination of a base, an upright column carried by the base, a block slidably interconnected to said column to be movable up and down thereon, adjusting means for adjustably fiidng the vertical position of said block on said column, a support carried by said block and movable therewith in accordance with the vertical position of said block, a pair of parallel arms having their inner ends pivotally carried by said block at vertically spaced positions, respectively, to swing up and down relative to said support, a link pivotally connected to the free ends of said parallel arms to move in a vertical path, mounting means for mounting an electrolytic markdevice thereto to move up and down therewith relative to a reference location where an article to be marked may be placed, an electric motor, and an eccentric driving device operatively connected to said motor to be rotated thereby, said eccentric driving device being carried by said support and movable therewith in accordance with the vertical position of said support, a crank arm member interconnecting said eccentric driving device and one of said parallel arms to swing said arms up and down upon rotation of said eccentric driving device, first electric circuit means for energizing the said electrolytic marking device, second electric circuit means for energizing said motor, and correlating control means for controlling said first and second electric circuit means to cause energization of the said marking device after said motor has caused the said arms to move down to where an electrolytic marking device carried by said link is at an elevation for marking an article at said reference location.

7. The combination as defined in claim 6 and including resiliently yieldable means to resiliently yieldably permit said arms to not swing downwardly upon being opposed by a resistance beyond a predetermined degree upon said arms moving a said marking device to an article to be marked.

8. The combination as defined in claim 6 and including timing means controlling the said second circuit means to operate the motor and the swinging of said arms thereby in a predetermined cycle of time periods for up and down movements and rests therebetween.

9. The combination as defined in claim 6 and including automatic control means for controlling the operation of the motor for swinging of the arms in a continuous timed sequence, manually operating control means for controllying the operation of the motor and swinging of the arms up and down in separate steps, and selective switch means for alternately connecting the automatic control means and the manually operating control means in said second electric circuit means energizing said motor.

10. Apparatus for the electrolytic marking of metal articles comprising the combination of, an electrolytic marking device adapted to be placed at a marking position for contacting and marking the surface of a said article at a reference location, first means supporting said marking device and adapted to carry the same in a path normal to the plane of said surface, second means driving said first means to move the marking device a predetermined distance toward and away from said surface, third means adapted to be connected to said second means for timing the operation of said second means and adapted to predetermine the time periods of the said marking device at said position and of intervals therebetween, and fourth means for electrically energizing the marking device during they time period that the marking device is at said position.

11. Apparatus as defined in claim 10 and in which said first means includes resiliently yieldable means adapted to cause the first means to resiliently yield upon the marking device moving in said path encounters resistance beyond a predetermined degree within said predetermined distance.

12. Apparatus as defined in claim 10 and in which said first means includes adjustable means for adjustably determining the lower limit of the movement or" the mark ing device said predetermined distance in said path relative to said reference location.

13. Apparatus as defined in claim 10 and including fifth means for selectively disconnecting the third means from the second means and for permitting manual control of the second means.

14. In combination, a base member, an upright carried by and extending upwardly from the base member, a block member movable upwardly and downwardly along said upright member, securing means for securing the block member to the upright member at a selected elevation of a plurality of elevations therealong, a bracket member carried by said block member and movable therewith relative to said base member, an electric motor carried by said bracket member, an eccentric driving device mounted to the motor and rotatable thereby, a pair of parallel arms disposed at a distance one above the other, pivot means pivotally connecting adjacent ends of said arms to said block member to permit swinging of said arms upwardly and downwardly on said pivot means, a link pivotally connected to the free ends of said arms to provide for their swinging together in parallel relationship, a crank member operatively connecting said eccentric driving device and a said arm to cause said arms to swing up and down upon rotation of said eccentric driving device, holding means for supporting an electrolytic mar g device by the free ends of said arms to move the marking device up and down with said arms, first electric circuit means for energizing said marking device, second electric circuit means for energizing said motor, and control means for automatically causing energization of the marking device by the first electric circuit upon the downward movement of the marking device to its lowermost position.

15. The combination defined in claim 14 and including settable timing means for controlling the operation of the said motor by said second electric circuit means to fix the time periods for the upward and downward movements of said arms and of the intervals between said movements.

References Cited in the file of this patent UNITED STATES PATENTS 2,491,910 Schinske Dec. 20, 1949 2,532,908 Hangosky et a1 Dec. 5, 1950 2,797,163 Eigher et a1. -June 25, 1957 2,798,849 Lindsay July 9, 1957 2,967,813 Lindsay Jan. 10, 1961 

1. ELECTROLYTIC MARKING APPARATUS COMPRISING THE COMBINATION OF A BASE, WORK-PIECE ENGAGING MEANS SUPPORTED IN JUXTAPOSITION TO SAID BASE TO HOLD A WORK-PIECE AT A REFERENCE LOCATION RELATIVE TO SAID BASE, A COLUMN MEMBER CARRIED BY SAID BASE IN UPRIGHT POSITION, A BLOCK MEMBER ADJUSTABLY MOVABLE ALONG SAID COLUMN MEMBER TO SELECTED ELEVATED POSTITIONS, ADJUSTING MEANS FOR ADJUSTABLY MOVING SAID BLOCK MEMBER ALONG SAID COLUMN MEMBER AND SECURING THE BLOCK MEMBE AT A SELECTED ELEVATED POSITION, A PAIR OF PARALLEL ARMS HAVING THEIR INNER ENDS PIVOTALLY CONNECTED TO SAID BLOCK MEMBER AT SPACED LOCATIONS, A LINK MEMBER PIVOTALLY CONNECTED TO THE FREE ENDS OF SAID AT SPACED LOCATIONS, AN ELECTROLYTIC MARKING DEVICE HAVING AN ELECTRODE DISPOSED AXIALLY THEREOF AND CARRIED BY SAID LINK MEMBER IN UPRIGHT POSITION, SAID ELECTROLYTIC MARKING DEVICE HAVING A LATERALLY DISPOSED FACE PORTION ADAPTED TO OPPOSINGLY ABUT A WORK-PIECE HELD BY SAID ENGAGING MEANS DURING ELECTROLYTIC MARKING OF SAID WORK-PIECE, AN ELECTRIC MOTOR CARRIED BY SAID BASE, AN ECCENTRIC DRIVING DEVICE ROTATABLE BY SAID MOTOR, CONNECTING MEANS INTERCONNECTING SAID ECCENTRIC DRIVING DEVICE AND A SAIR PARALLEL ARM TO SWING SAID PARALLEL ARMS UP AND DOWN BY THE ROTATION OF SAID ECCENTRIC DRIVING DEVICE, SAID CONNECTION MEANS INCLUDING RESILIENT MEANS TO RESILIENTLY YIELD UPON THE SAID ARMS BEING SWUNG DOWNWARDLY BEYOND A LIMIT DETERMINED BY THE POSITION OF A SAID WORK-PIECE OPPOSINGLY ABUTTED BY SAID FACE PORTION OF THE ELECTROLYTIC MARKING DEVICE, AND AUTOMATIC TIMING MEANS CONTROLLING THE ACTUATION OF SAID ECCENTRIC DRIVING DEVICE TO PREDETERMINATELY FIX THE TIME PERIODS OF THE UP AND DOWN MOTIONS OF THE SAID ARMS AND RESTS AT THE LIMITS OF MOVEMENT OF SAID ARMS. 